Golf club weighting system with under-grip retention

ABSTRACT

In a novel approach to golf club counter-weighting, directed to incorporation in a golf club at original manufacture as well as in the after-market, required secure longitudinal retention of the weighting device is accomplished by structure differing from known practice in that the required longitudinal retention is referenced to the top end surface of the golf club shaft by an annular flange configured at the top end of the weighting device and held securely between the cap portion of an original unmodified golf club grip and the top end of the shaft, thus accomplishing the required longitudinal retention of the weighting device with no need for grip modification or friction-gripping the interior surface of the shaft. The flange diameter is sized to fit closely inside the grip so as to also provide lateral retention at the top end of the thusly cantilevered weighting device.

PRIORITY

Benefit is claimed under 35 U.S.C. 119(e) of provisional application 62/253,138, filed Nov. 10, 2015.

FIELD OF THE INVENTION

The present invention relates to the field of sports equipment, and more particularly to golf club counter-weighting for enhancing a golfer's playing and score by more optimally matching the golf club to the dynamic physical characteristics of the individual golfer, by adding a weighting device with at least one weight element within a selected upper portion of a hollow golf club shaft.

BACKGROUND OF THE INVENTION

There has been an evolution in golf club technology that has led to ultra light-weight thin-wall hollow shafts. These have aroused concerns about optimally matching the amount of mass, including its location and distribution in the golf club, to the physical characteristics of the individual golfer, considering swing dynamics.

Along with attention that has been given to optimizing the mass at the club head end for the lightweight shaft, there has been recognition that better control, distance and accuracy can be obtained by counterbalancing the mass of the club head by the addition of mass at one or more locations in the upper portion of the shaft, where a judicial amount of mass can be selected to optimally match the player's physiological characteristics.

Typically, a weighting device includes at least one weight element, a.k.a. “counterweight” and “swing-weight” for installation inside the shaft of a previously manufactured golf club; special mounting arrangements are required to provide lateral retention to prevent vibration and metal-to-metal contact, and longitudinal retention to prevent displacement of the added weight element assembly relative to the shaft due to slippage under the stresses of handling and actual golf play.

Unwanted metal-to-metal contact can be avoided by allowing adequate spacing between the weighting device and the interior shaft surface. Alternatively, the unwanted contact can be avoided by installing resilient material, typically foam, therebetween in the form of at least one sleeve surrounding the weight element(s) or a lining inside the shaft. With judicious selection of resilience and thickness dimensioning for optimal working compression, the intervening resilient material can further provide optimal vibration damping and longitudinal retention.

DISCUSSION OF KNOWN ART

In the practice of known art, implementations for providing the required longitudinal retention fall into two main categories:

Category (1): securing to the golf club grip, requiring modification of the cap region of a previously manufactured golf grip for access to enable insertion, locking in place, adjustment and removal of added weight elements, since golf grips are originally made with either no opening or a very small central air pressure vent opening; and

Category (2) retention via friction against the interior surface of the golf club shaft, either by (2a) one or more expansion plugs attached to (or constituting) weight elements, typically requiring special tools for installation, location adjustment and removal, (2b) resilient sleeves on weight elements, or (2c) a resilient lining at the shaft interior surface.

Subcategories (2b) and (2c) require a judicious tradeoff between compressive holding force and enablement of adjustment and removal, and special compensation and/or limitations regarding tapered shaft locations, unless implemented in conjunction with Category (1).

U.S. Pat. No. 7,481,716 issued Jan. 27, 2009 for GOLF GRIP FOR ACCOMMODATING SELECTABLE WEIGHT ASSEMBLY by J. Johnson, the present inventor, discloses an example of category (1) implemented with the grip cap modified by a stepped circular opening, in conjunction with category (2a).

U.S. Pat. No. 8,177,658 for WEIGHT DEVICE ADJUSTABLY SECURED IN GOLF CLUB SHAFT by J. Johnson, the present inventor, discloses an example of category (1) implemented with the grip cap modified by a (non-stepped) simple circular opening, in conjunction with category (2a).

U.S. Pat. No. 8,641,551 for VERSATILE VIBRATION-DAMPED GOLF CLUB SWING WEIGHT (and a division thereof, pending U.S. patent application Ser. No. 14/307,494 for VERSATILE VIBRATION-DAMPED GOLF CLUB SWING WEIGHT METHOD), by J. Johnson, the present inventor, disclose (FIG. 6) an example of category (1) implemented with the grip cap modified by a circular opening fitted with a cap plug configured with a stepped circular opening, in conjunction with category (2a).

The foregoing descriptions relate to weighting devices for adding inside the shaft of a previously manufactured golf club. There remains an unfulfilled need for a more elegant simplified implementation of a weight device, enabled with the required longitudinal retention thereof, that can be incorporated in a golf club either at original manufacture or in the aftermarket.

OBJECTS OF THE INVENTION

It is a primary object of the present invention to provide an elegant simplified weighting device implementation that is inherently and securely retained longitudinally, and that is readily and easily incorporated into golf clubs at original manufacture as well as in the aftermarket.

SUMMARY OF THE INVENTION

The foregoing object has been met by the disclosed novel approach to golf club counter-weighting, directed to incorporation in a golf club at original manufacture as well as in the after-market, required secure longitudinal retention of the weighting device is accomplished by structure differing from known practice in that the required longitudinal retention is referenced to the top end surface of the golf club shaft by an annular flange configured at the top end of the weighting device and held securely between the cap portion of an original unmodified golf club grip and the top end of the shaft, thus accomplishing the required longitudinal retention of the weighting device with no need for grip modification or friction-gripping the interior surface of the shaft. The flange diameter is sized to fit closely inside the grip so as to also provide lateral retention at the top end of the thusly cantilevered weighting device.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further objects, features and advantages of the present invention will be more fully understood from the following description taken with the accompanying drawings in which:

FIG. 1 is a cross-sectional elevation a basic weighting device of the present invention installed in the grip region of a golf club shaft.

FIG. 2 is an enlarged view of an upper portion of the subject matter of FIG. 1.

FIG. 3 is an elevational view of the weighting assembly shown in FIGS. 1 and 2.

FIGS. 4-7 each show a cut-away cross-section of the upper end portion of a golf club shaft equipped with alternative weighting device support structure embodiments.

FIG. 8 shows an alternative weighting device utilizing a machine bolt countersunk in the flange part, extending downwardly and engaging a threaded weighting component.

FIG. 9 shows a version of the weighting device of FIG. 8 modified by the addition of an unthreaded bored weighting component interjected between the flange part and the threaded weighting component.

DETAILED DESCRIPTION

The above and further objects, features and advantages of the present invention will be more fully understood from the following description taken with the accompanying drawings in which:

FIG. 1 is a cross-sectional elevation of the upper portion of a golf club 10 equipped with a basic weighting device 12 secured longitudinally from the top end surface of shaft 10A in accordance with the present invention.

FIG. 2 is an enlargement of an upper portion of FIG. 1 showing a top central air vent hole 10B and showing an installed weighting device 12 comprising a weight element 12A of heavy-weight metal configured with a top flange 12A′ sandwiched between the top end surface of shaft 10A and the lower surface of the cap region of grip 10B thus inherently providing stable positive longitudinal securing, as well as lateral securing of an upper portion of weight element 12A by sizing the diameter of flange 12A′ for a close fit inside the grip 10B, thus holding weight 12A cantilevered securely in place in its working location in shaft 10A in accordance with the present invention.

Flange 12A′ is made as thin as possible while preserving adequate structural integrity, so as to minimize upward displacement of the grip 10B from its normal location on shaft 10A. Optionally flange 12A′ may be tapered slightly to decrease in thickness toward the outer edge, e.g. tapering from ˜0.04″ thick in a 0.375″ diameter central location of the weight assembly element to ˜0.03″ thick at the peripheral edge of the flange 12A′, where the diameter is typically 0.62″.

Lateral retention of the lower portion of cantilevered weight element 12A is provided by a sleeve 12B made from resilient material, e.g. foam, surrounding the lower end region of weight element 12A. Sleeve 12B is typically fastened adhesively to weight element 12A and is judiciously dimensioned in thickness so as to bear against surrounding shaft interior surface and thus provide lateral constraint, vibration damping and avoidance of metal-to-metal contact.

In this basic embodiment the weighting device 12 consists of the flanged weight element 12A with sleeve 12B; the weighting system further includes the enclosed cap portion of the grip 10B and the upper end of shaft 10A co-operating to act in a clamping manner on flange 12A′ so as to retain weight element 12A securely cantilevered in its working location in shaft 12A.

As an alternative to sleeve 12B, a designated portion of the upper interior surface of shaft 12B could be lined with equivalent resilient material, e.g. foam, optionally fastened adhesively

In the event that the required swing weight is relatively small, in an even more basic embodiment, as a matter of design choice, the weighting device could be implemented by a relatively small flanged weight element 12A alone, omitting sleeve 12B and relying on sufficiency of the surrounding air gap clearance.

FIG. 3 is an elevational view of the flanged weighting device 12 of FIGS. 1 and 2, consisting of weight element 12A with its topside integral flange 12A′ and surrounded at its lower portion resilient sleeve 12B.

FIGS. 4-9 depict exemplary weight device versions as alternatives to the basic embodiment, weight device 12, FIGS. 1-3. FIG. 4-, each show a cut-away cross-section of the upper end portion of a golf club shaft 10A, supporting a weighting device functionally equivalent to the one-piece weight element construction shown in FIGS. 1-3 but with the flange part made separately and affixed directly or indirectly onto the top end of a cylindrical weighting component (weight element or spacer), shown cut-away at the underside.

This configuration allows the flange part to be made from robust metal such as stainless steel while the attached element can be either a single weight element, as shown, made of dense metal, or a spacer of low-density metal or non-metal material for lighter weight, with the further option of making the bottom end (shown cut-off) attachable to additional items selected from a wide variety of available weighting components (weight elements, spacers sleeves and expanders) that can be removably tandemed in series.

FIG. 4 shows threaded male/female coupling, i.e. attachment via a threaded downward extension of the flange part 12D engaging a threaded opening in the top end of cylindrical weight element 12C.

FIG. 5 shows plug-socket coupling, i.e. non-threaded, typically adhesive attachment via engagement of a cylindrical opening in the top end of cylindrical weight element 12E, closely fitted to a tubular downward extension of the flange part 12F, configured with an open top end forming a recessed region which, for a grip intended for removal by compressed air, could facilitate such removal by enabling insertion of an air nozzle/probe through the grip vent hole (10B′, FIG. 2).

FIG. 6 shows an alternative threadedly-coupled weighting device wherein the weight element 12G is configured with a threaded upward extension of reduced diameter engaging threads inside a tubular downward extension of the flange part 12H.

FIG. 7 shows socket-plug coupling; attachment via engagement of the unmodified cylindrically-shaped top end of weight element 12J fitted closely into a tubular downward extension of the flange part 12K.

FIG. 8 shows an alternative weighting device similar to that shown in FIG. 4 in that the weight element 12C is attached via its threaded opening: however in FIG. 8, the flange part 12L is unthreaded and instead is configured to accept a machine bolt 12M, with its cavity-driven head countersunk, extending downwardly through an unthreaded concentric opening to threadedly engage and securely attach weight element 12C.

FIG. 9 shows a version of the weighting device of FIG. 8 modified by the addition of an unthreaded bored weighting component 12N, typically a lightweight spacer interjected between flange part 12J and threaded component 12C, typically a dense metal weight element.

The present invention can be implemented, as a matter of design choice, with the flange part and associated weighting device elements made solid or made tubular, i.e. configured with a co-axial through-opening, unthreaded e.g. as in FIGS. 5 and 7. Attachment and securing of associated elements may be implemented threadedly, e.g. as in FIGS. 4, 6, 8 and 9, or unthreaded elements as in FIGS. 5 and 7 may be secured adhesively.

The invention may be embodied and practiced in other specific forms without departing from the spirit and essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, and all variations, substitutions and changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. 

What is claimed is:
 1. A golf club weighting system, for installation at an upper region of an upright open-top hollow golf club shaft having a flat annular top end surface with designated inner and outer diameter, comprising: a weighting device, made from relatively heavy metal, configured topside with a flange portion having a circular planar top surface and configured underside with (a) an annular flat surface forming a circular flange with an outer diameter substantially equal to the outer diameter of the top end surface of the shaft and an inner diameter less than the inner diameter of the shaft top end, and (b) a cylindrical weight element portion configured as an axial downward extension of the flange portion, made integral therewith and having an outer diameter equal to the inner diameter of the flange portion; said weighting device being installed downwardly into the open top end of the shaft with the flange portion seated coaxially interfacing and bearing down on the top end surface of the shaft so as to upwardly support the weight element portion disposed within the shaft in a designated working location, extending downwardly from the flange portion; and a golf club grip of resilient material, sized and shaped to fit closely over an upper portion of the shaft, secured in place frictionally, configured with an integral cap portion forming a topside enclosure made and arranged to interface and bear down onto the planar top surface of the flange portion whereby the flange, thusly constrained firmly between the cap portion of said grip and the top end surface of the shaft, serves to constrain said weight element longitudinally, cantilevered in the working location within the shaft.
 2. The golf club weighting system as defined in claim 1 wherein said weighting device further comprises a resilient sleeve, surrounding a designated portion of said weight element, sized to bear against surrounding shaft interior surface and thus provide lateral constraint, vibration damping and avoidance of metal-to-metal contact.
 3. The golf club weighting system as defined in claim 1 further comprising a resilient lining of resilient material adhesively applied around an inner shaft surface extending over a designated area corresponding to potential working locations to be occupied by a weight element, said lining being sized to bear against a contained weight element so as to provide the weight element with required lateral constraint, vibration damping and avoidance of metal-to-metal contact
 4. The golf club weighting system as defined in claim 1 wherein said grip is configured with a relatively small vent opening configured topside traversing the cap portion co-axially for purposes of preventing air pressure surge build-up within the shaft during installation of said grip.
 5. The golf club weighting system as defined in claim 1 wherein said weight element is configured underside with weighting-component-attachment structure made and arranged to enable removable attachment of an additional weighting component.
 6. The golf club weighting system as defined in claim 5 wherein the weight element's weighting-component-attachment structure comprises a member of a male/female threaded coupling pair, and the weighting device is thusly configured with at least one additional weighting component selected from a pair of structures including (1) an additional weight element, and (2) a spacer of relatively light-weight material, configured topside and underside with a member of a male/female threaded coupling pair, and thusly attached underside to an additional weight element thusly secured, located at a desired working location in the shaft.
 7. A golf club weighting system comprising: (1) a weighting device, for installation at an upper region of an upright open-top hollow golf club shaft having a flat annular top end surface with designated inner and outer diameter, comprising: (a) a flange portion, disposed topside in said weighting device, having a circular planar top surface and configured underside with (1) an annular flat surface forming a circular flange with an outer diameter substantially equal to the outer diameter of the top end surface of the shaft and an inner diameter less than the inner diameter of the shaft top end, and (2) weighting-component-attachment structure comprises a member of a male/female coupling pair; (b) a weighting portion, including at least one cylindrical weight element, attached to said flange portion underside thereof via the flange portion's weighting-component-attachment structure; (2) said weighting device being installed downwardly into the open top end of the shaft with the flange portion seated coaxially interfacing and bearing down on the top end surface of the shaft so as to upwardly support the weight element portion disposed within the shaft in a designated working location, extending downwardly from the flange portion; and (3) a golf club grip of resilient material, sized and shaped to fit closely over an upper portion of the shaft, secured in place frictionally, configured with an integral cap portion forming a topside enclosure made and arranged to interface and bear down onto the planar top surface of the flange portion whereby the flange, thusly constrained firmly between the cap portion of said grip and the top end surface of the shaft, serves to constrain said weight element longitudinally, cantilevered in the working location within the shaft.
 8. The golf club weighting system as defined in claim 7 wherein the flange portion's male/female coupling pair structure is configured as a plug/socket pair secured together adhesively.
 9. The golf club weighting device as defined in claim 7 wherein the flange portion's weighting-component-attachment structure is made and arranged to enable removable attachment of the weighting portion to the flange portion.
 10. The golf club weighting system as defined in claim 9 wherein the flange portion's weighting-component attachment structure is configured as a member of a male/female threaded coupling pair, thus providing removable attachment of the weighting portion to the flange portion.
 11. The golf club weighting system as defined in claim 10 wherein said flange portion's weighting-component-attachment structure comprises: a downward cylindrical shaped extension of the circular flange portion, made smaller in diameter than the designated inner top end shaft diameter, the flange portion, including said extension, being traversed by a coaxial cylindrical through-opening with an enlarged upper end portion; and a machine screw with a head portion recessed in the enlarged upper end portion of the through-opening and a threaded portion extending down through the through-opening so as to enable engagement with a mating threaded opening of a weighting component thusly attached therebeneath.
 12. The golf club weighting system as defined in claim 10 further comprising: a cylindrical weight element, of relatively heavy-weight material, constituting a weighting component, configured with a coaxial threaded opening mating and engaged by said machine screw and thereby attached and secured in place, located immediately beneath said flange portion, at a desired working location in the shaft.
 13. The golf club weighting system as defined in claim 12 wherein said weighting device further comprises a resilient sleeve, surrounding a designated portion of said weight element, sized to bear against surrounding shaft interior surface so as to provide the weight element with required lateral constraint, vibration damping and avoidance of metal-to-metal contact.
 14. The golf club weighting system as defined in claim 12 further comprising a resilient lining of resilient material adhesively applied around an inner shaft surface extending over a designated area corresponding to potential working locations to be occupied by a weight element, said lining being sized to bear against a contained weight element, thusly provided with required lateral constraint, vibration damping and avoidance of metal-to-metal contact.
 15. The golf club weighting system as defined in claim 11 further comprising: a cylindrical spacer, of relatively light-weight material, configured with a cylindrical coaxial through=opening, interposed between the flange portion and the weighting component; said machine screw, extending through and beyond the spacer through-opening, so as to enable engagement with a mating threaded opening of a weighting component thusly attached therebeneath.
 16. The golf club weighting system as defined in claim 15 further comprising: a cylindrical weight element, of relatively heavy-weight material, constituting a weighting component, configured topside with a coaxial threaded opening mating and engaged by said machine screw and thereby attached and secured in place, located beneath said spacer and thereby displaced from said flange portion by a designated dimension of said spacer, and thus secured at a desired working location within the shaft.
 17. The golf club weighting system as defined in claim 16 wherein said weighting device further comprises a resilient sleeve, surrounding a designated portion of said weight element, sized to bear against surrounding shaft interior surface and thus provide lateral constraint, vibration damping and avoidance of metal-to-metal contact.
 18. The golf club weighting system as defined in claim 1 further comprising a resilient lining of resilient material adhesively applied around an inner shaft surface extending over a designated area corresponding to potential working locations to be occupied by a weight element, said lining being sized to bear against a contained weight element so as to provide the weight element with required lateral constraint, vibration damping and avoidance of metal-to-metal contact. 